Sonny Bill Williams says his scheduled November 24 fight with Francois Botha is in doubt due to a pectoral muscle injury suffered playing rugby in Japan.

UPDATE: According to our friends at Aus-Boxing.com, the bout has been officially postponed. Williams will undergo surgery, which could result in 2-3 months of physical rehabilitation.

With Japanese rugby on a five-week break, All Blacks centre and New Zealand heavyweight champion Williams has arrived in Sydney to prepare for the Botha fight but said he needed to get scans on the injury suffered playing for his club Panasonic at the weekend.

"At the moment, it [the fight] is a little bit in doubt," Williams told Fox Sports at Sydney airport.

"I just came back here straight away ... I've got to get some scans and see how the pec is ... see the extent of the injury."

Williams is expected to join the Sydney Roosters in a return to the NRL for 2013 but said he wouldn't sign a deal until his rugby stint in Japan was over.

Tags: Francois Botha , Sonny Bill Williams